| 摘要 |
PURPOSE:To quickly activate a catalyst device by controlling opening operation of an exhaust cut valve when a temperature which relates to an exhaust catalyst device is low, in a device which opens the exhaust cut valve only at a high flow range of intake air so as to activate a secondary supercharger. CONSTITUTION:In a two-cylinder engine, turbines 105, 107 of primary and secondary turbosuperchargers 104, 106 are provided at two exhaust passages 102, 103 provided corresponding to cylinders, respectively. The two exhaust passages 102, 103 are communicated by a communication passage 112 at the upstream side of the turbines 105, 107. An exhaust cut valve 123 which is opened only at a high flow range of intake air is provided at the right down stream of a communication passage 122 opening position of secondary side exhaust passage 103. In this case, a temperature sensor 182 which detects temperature of exhaust gas is provided at a converged exhaust passage 124 located at the upstream of a catalyst device 181. Consequently, when the detected temperature is lower than a specified level, opening operation of the exhaust cut valve 123 is controlled. |
